Future emissions requirements for Diesel Engines around the world will require engine concepts capable of achieving low NOx and low PM emissions while at the same time having a high integration of components/functions for low system cost and smallest package. Exhaust gas recirculation (EGR) valves and EGR cooler bypass valves are usually constructed as two separate valves.
However, often time having two valves to perform the function of delivering exhaust gas to an EGR cooler, or bypass the EGR cooler and deliver the exhaust gas directly into the intake manifold of the engine can be more costly due to the increased amount of components, or may be limited by packaging constraints.
Accordingly, there exists a need for a single valve to perform the function of selectively metering exhaust gas through an EGR cooler, as well as having the ability to bypass the EGR cooler partially or completely.